This revised application describes the initial research in a programmatic series of studies investigating augmentative communication abilities in children with cerebral palsy (CP). Two preliminary studies are proposed to describe and validate cognitively-based skills necessary for use of augmentative communication devices using picture (icon) stimuli and semantic compaction. Semantic compaction is the use of multiple associations to icons to represent and communicate messages (e.g., a "sun icon" may "mean" hot, round, or yellow, depending on the context). Semantic compaction skills, such as the ability to form multiple associations to a single icon, will be investigated in 4-, 5-, and 6-year-old children with CP with (a) motor control sufficient for manual pointing to icons and (b) children capable of eye pointing only. Study 1 will compare semantic compaction skills of the two groups of children with CP with the skills of a sample of able bodied children using the Semantic Compaction Competency Profile developed by the investigators. This task requires manual or eye pointing to an icon or series of icons representing a concept or sentence. It is expected that both groups of children with CP will differ from the able bodied children and that the manual point group will perform at a higher level than the eye point group, especially on the semantic compaction skills requiring sequencing. These differences are expected to decrease with age, lending credence to the hypothesis that cognitively-based semantic compaction skills may be associated with experiential variables that are important early in development but decrease in importance with age. Study 2 will determine if measures of semantic compaction skills are valid predictors of a child's ability to learn to use a communication device using semantic compaction (IntroTalker). This device is a dedicated microcomputer interfaced to a voice synthesizer and has a keyboard of icons instead of alphanumeric symbols. If semantic compaction skills are related to abilities to learn to use such augmentative communication devices, then children with high scores on measures of semantic compaction will learn to communicate more rapidly than children scoring low. Further, measures of semantic compaction skill should prove to be better predictors of the efficiency of learning to communicate than general measures of language abilities such as the PPVT-R and TACL-R. These preliminary studies will lead to a series of studies investigating the factors influencing optimal augmentative communications in children with CP with different degrees of motor involvement.